I also have no interest in ending up in a nursing home. When I get past middle age, I'm considering doing what so many of us did right after college. Namely finding 5-6 like-minded people of the same age and go in for equal shares on a big house.
We can take turns driving each other to doctor's appointments, share the financial costs of housing and groceries, take turns doing chores. (Hopefully a house of senior citizens would be better at that than a house of 20-somethings were in my experience.)
And when my health fails past a certain point, I don't plan on jumping through too many hoops to drag out the end. As a very religious person, I don't think God requires us to hang on for every possible minute of painful misery that modern medicine can inflict.
I read once in a Reader's Digest that something like 90% of a person's lifetime medical costs in the US go into their last 30 days of life. (I wish I had that article now, I'm sure it had other pertinent information.) I see no reason to spend a dime just to endure a lingering death, complete with nasal tubes, colostomy bags and bed sores. A more appealing alternative can be found here:
http://www.straightdope.com/mailbag/meskimoicefloe.html